Mask blank, transfer mask, and method for manufacturing semiconductor device

Abstract

A mask blank including a light shielding film pattern having high ArF light fastness. The light shielding film is on a transparent substrate. In the mask blank, the light shielding film is a single layer film formed of a material containing silicon and nitrogen, and the light shielding film has an optical density to an ArF excimer laser exposure light of 2.5 or more, a surface reflectance to the exposure light of 40% or less, a back-surface reflectance to the exposure light of 40% or less, a transmittance to a light having a wavelength of 900 nm of 50% or less, an extinction coefficient to a light having a wavelength of 900 nm of 0.04 or more, and a thickness of 60 nm or less.

The invention claimed is: 
     
       1. A mask blank comprising:
 a transparent substrate; and 
 a light shielding film on the transparent substrate, 
 wherein the light shielding film includes:
 a lower layer on the transparent substrate; and 
 an upper layer on the lower layer, 
 
 wherein the lower layer contains silicon and nitrogen, 
 wherein the upper layer contains silicon and oxygen, 
 wherein an optical density to an ArF excimer laser exposure light of the light shielding film is 2.5 or more, 
 wherein a surface reflectance to the exposure light of the light shielding film is 30% or less, 
 wherein a back-surface reflectance to the exposure light of the light shielding film is 40% or less, 
 wherein a transmittance to a light having a wavelength of 900 nm of the light shielding film is 50% or less, 
 wherein an extinction coefficient k to a light having a wavelength of 900 nm of the light shielding film is 0.04 or more, and 
 wherein a thickness of the light shielding film is 60 nm or less. 
 
     
     
       2. The mask blank according to  claim 1 , wherein the lower layer is made of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element. 
     
     
       3. The mask blank according to  claim 1 , wherein the upper layer is made of a material consisting of silicon and oxygen, or a material consisting of silicon, oxygen, and one or more elements selected from a semimetal element and a non-metal element. 
     
     
       4. The mask blank according to  claim 1 , wherein an extinction coefficient k to a light having a wavelength of 700 nm of the lower layer is 0.10 or more. 
     
     
       5. The mask blank according to  claim 1 , wherein a refractive index n to a light having a wavelength of 900 nm of the lower layer is 3.5 or less. 
     
     
       6. The mask blank according to  claim 1 , wherein a refractive index n to a light having a wavelength of 700 nm of the lower layer is 3.8 or less. 
     
     
       7. The mask blank according to  claim 1 , a refractive index n to the exposure light of the lower layer is 1.6 or more and 2.1 or less. 
     
     
       8. The mask blank according to  claim 1 , an extinction coefficient k to the exposure light of the lower layer is 1.6 or more and 2.1 or less. 
     
     
       9. The mask blank according to  claim 1 , wherein a hard mask film made of a material containing chromium is formed on the light shielding film. 
     
     
       10. A transfer mask comprising:
 a transparent substrate; and 
 a light shielding film having a transfer pattern on the transparent substrate, 
 wherein the light shielding film includes:
 a lower layer on the transparent substrate; and 
 an upper layer on the lower layer, 
 
 wherein the lower layer contains silicon and nitrogen, 
 wherein the upper layer contains silicon and oxygen, 
 wherein an optical density to an ArF excimer laser exposure light of the light shielding film is 2.5 or more, 
 wherein a surface reflectance to the exposure light of the light shielding film is 30% or less, 
 wherein a back-surface reflectance to the exposure light of the light shielding film is 40% or less, 
 wherein a transmittance to a light having a wavelength of 900 nm of the light shielding film is 50% or less, 
 wherein an extinction coefficient k to a light having a wavelength of 900 nm of the light shielding film is 0.04 or more, and 
 wherein a thickness of the light shielding film is 60 nm or less. 
 
     
     
       11. The transfer mask according to  claim 10 , wherein the lower layer is made of a material consisting of silicon and nitrogen, or a material consisting of silicon, nitrogen, and one or more elements selected from a semimetal element and a non-metal element. 
     
     
       12. The transfer mask according to  claim 10 , wherein the upper layer is made of a material consisting of silicon and oxygen, or a material consisting of silicon, oxygen, and one or more elements selected from a semimetal element and a non-metal element. 
     
     
       13. The transfer mask according to  claim 10 , wherein an extinction coefficient k to a light having a wavelength of 700 nm of the lower layer is 0.10 or more. 
     
     
       14. The transfer mask according to  claim 10 , wherein a refractive index n to a light having a wavelength of 900 nm of the lower layer is 3.5 or less. 
     
     
       15. The transfer mask according to  claim 10 , wherein a refractive index n to a light having a wavelength of 700 nm of the lower layer is 3.8 or less. 
     
     
       16. The transfer mask according to  claim 10 , a refractive index n to the exposure light of the lower layer is 1.6 or more and 2.1 or less. 
     
     
       17. The transfer mask according to  claim 10 , an extinction coefficient k to the exposure light of the lower layer is 1.6 or more and 2.1 or less. 
     
     
       18. A method of manufacturing a semiconductor device, the method comprising the step of exposure-transferring a transfer pattern on a resist film on a semiconductor substrate using the transfer mask according to  claim 10 .